In the conventional coin operated lockers, the coin slot and lock cylinder of a coin operated lock are respectively arranged in the upper side and lower side of a locker. After a coin is deposited, the key is withdrawn from the lock cylinder and kept by the user. Once the key is lost, the coin operated lock cannot be unlocked. The conventional coin operated lock has the following disadvantages:    1. The lock cylinder is arranged only in the lower side of a conventional coin operated locker. If the locker has been locked and the key should be lost, the latched lock tongue is hard to be unlocked with a tool in a short period of time. Thus, a locksmith is needed to break the lock, and an expense is also needed to repair or replace the lock.    2. Once the lock cylinder or lock tongue of a conventional coin operated lock is broken, the coin operated lock cannot work any more.